This application by a new investigator proposes a one year study to assess and reduce potential harm to ambulatory care patients, in keeping with the 2005 NAE/IOM report "Building a Better Delivery System" recommendation to team human factors and health care expertise to improve the safety of the health care system. The need to serve widely varying levels and types of demand for care places greater demand on ambulatory care to adapt, requiring the anticipation of possible threats to safety using the newly evolving approach of resilience. Rather than retrospective traditional risk assessment, resilience engineering shifts attention to a prospective view to anticipate what future events may challenge system performance. The proposed research will model the actual process of ambulatory care in emergency departments and outpatient clinics, identify potential risks and develop criteria for risk measurements / metrics, and organize the metrics and methods so that they can be generalized to other ambulatory care organizations. Research will be performed in two phases that consist of two cycles each. During Phase One team members at both research sites will collect data using observational study, interviews, flow analysis, critical incident study, and artifact analysis to produce a comprehensive process description of ambulatory care. [unreadable] Phase Two will analyze Phase One data using process tracing, operational sequence analysis, and case studies to enrich the Phase One maps. The project team will also develop criteria for metrics that can be used to quantify risk and monitor results following interventions. The result will be process maps of outpatient and ED ambulatory care settings with indications of risk for adverse outcomes and methods to monitor and reduce risk. Case studies and related materials will also be posted to a public web site so that ambulatory care facilities can study to develop countermeasures that can be employed to intervene and mitigate or eliminate hazards that threaten patient and care provider safety. [unreadable] [unreadable] [unreadable]